The present invention relates to a signal receiver for tire air pressure monitoring system that intermittently receives tire pressure detection signals sent from signal transmitters of a tire air pressure monitoring system, and particularly to a signal receiver for tire air pressure monitoring system that is capable of reducing the power consumption during a vehicle engine stop state.
A tire air pressure monitoring is proposed to detect air pressure of vehicle tires. This tire pressure monitoring system includes signal transmitters that detect the tire air pressure and transmit radio-wave tire pressure detection signals and a signal receiver that receives the tire pressure detection signals sent from the signal transmitters. The tire pressure monitor system needs to sense the tire air pressure even during the engine stop state so that it indicates the tire pressure to a vehicle driver before the vehicle starts to run. The signal transmitters and receiver are designed to operate intermittently to send and receive the pressure detection signals so that the power consumption during the engine stop state is reduced.
The proposed receiver, however, cannot have a long rest period due to the need of certain reception of the pressure detection signals sent from the transmitters. Specifically, the transmitters and receiver are not synchronous in their operations, and therefore the receiver has a shorter rest period relative to the transmitters thereby not to miss pressure detection signals.
It is therefore an object of the present invention to provide a signal receiver for a tire air pressure monitoring system capable of reducing the power consumption during the engine stop state.
In order to achieve the above objective, a signal receiver for a tire air pressure monitoring system receives an air pressure detection signal sent from a signal transmitter while turning on the power supply intermittently. The receiver includes an intermittent operation time control circuit that activates intermittently a partial or entire function of the receiver during a first predetermined period and deactivates the partial or entire function of the receiver during a second predetermined period that follows the first period. This intermittent operation time control circuit repeats the activation and deactivation alternately.
The partial receiver function is the function of a receiving section, or the functions of a control circuit section excluding the intermittent operation time control circuit and the receiving section. Alternatively, the intermittent operation time control circuit may be equipped in the outside of the receiver to control the entire receiver function.
The basis of deactivating the receiver function partially or entirely during the second predetermined period is that the tire air pressure generally varies less in a long duration of the engine stop state. In other words, during the parking of a vehicle, the necessity of updating tire pressure data in short time intervals decreases.